Well Cleaning Tool

ABSTRACT

A well cleaning tool including a tubular body, a cylindrical sleeve and at least one scratching element. The tubular body includes a threaded lower end for attaching to an end cap, and a plurality of first passages. The cylindrical sleeve is sized to receive the tubular body and includes a plurality of second passages such that the second passages are in alignment with the first passages. The at least one scratching element is preferably a rigid cable with frayed ends that is passed through the aligned first and second passages such that the frayed ends outwardly extend from an outer surface of the sleeve. Threading or tightening the tubular body lower end to the end cap will cause the first and second passages out of alignment, causing the rigid cable to crimp or pinch between the first and second passages, retaining the rigid cable in place.

CROSS REFERENCES TO RELATED APPLICATIONS

U.S. Provisional Application for Patent No. 61/519,413, filed May 17,2011, with title “Well Cleaning Tool” which is hereby incorporated byreference. Applicant claim priority pursuant to 35 U.S.C. Par.119(e)(i).

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSOREDRESEARCH AND DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a well cleaning tool for removingdebris accumulated in a well casing and, more particularly, to such atool having a plurality of bristles or scratching elements for removingthe debris. The well cleaning tool may be used alone, but may also beused in combination with solvents and/or cleaning fluids which assist inremoval of the debris. Such debris typically comprises of drillingfluid, cement compositions, pipe joint compositions and other materials.

2. Brief Description of Prior Art

Oil, gas, water and other types of wells almost always employ a steelpipe or well casing to ensure the integrity of the well borehole. Thewell casing is cemented during the completion stage of a drillingoperation.

The optimization of production is an important criteria of anycompletion. Studies have shown that residue on the internal diameter ofthe well casing (such as cement, pipe joint composition, scale, burrs,etc.) have a negative impact on productivity. Therefore, a majoremphasis has been made to clean the inner diameter of the well casing.Thus, when the operators have finished the pumping of cement compositionthrough the well casing, a work string is lowered on which a mechanicalscraping device is used to scrape the walls of the casing. Cleaning ofthe well casing is also necessary at intervals during well production toremove debris and residues, such as oil, paraffin and scale which haveaccumulated on the well casing wall.

Well casing scrapers are well known in the art. However, the scrapingaction of a traditional scraper with blades have been known to beineffective. In addition, such prior art scraping devices have beencomplicated to assemble and maintain.

Therefore, there is a need for a down hole assembly that will beeffective in cleaning the well casing. There is also a need for a downhole assembly that incorporates bristles as the scraping element thatare a sturdy construction and allow for ease of replacement.

As will be seen from the subsequent description, the preferredembodiments of the present invention overcome shortcomings of the priorart.

SUMMARY OF THE INVENTION

A well cleaning tool is disclosed. The well cleaning tool generallyincludes a hollow tubular body, a cylindrical sleeve and scratchingelements. The tubular body includes a threaded lower end for attachingto an end cap, and a plurality of passages. The hollow cylindricalsleeve is sized to receive the tubular body. Like the tubular body, thecylindrical sleeve includes a plurality of passages such that thepassages of the sleeve are in alignment with the passages of the tubularbody.

The scratching element is preferably a rigid cable with frayed ends thatis passed through the aligned passages of the sleeve and tubular bodysuch that the frayed ends extend from an outer surface of the sleeve.Threading or tightening the tubular body lower end to the end cap willcause the passages out of alignment, causing the rigid cable to crimp orpinch between the passages of the sleeve and tubular body, fixing therigid cable in place.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the preferred embodiment of the presentinvention, a well cleaning tool.

FIG. 2 is an exploded view of the well cleaning tool illustrated in FIG.1.

FIG. 3 is a partial sectional view of the well cleaning tool illustratedin FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In accordance with the present invention, a well cleaning tool forcleaning a well casing is disclosed. Briefly stated, the presentinvention is directed to a well cleaning tool having a plurality ofbristles or scratching elements for removing debris on the internaldiameter of the well casing. In the broadest context, the well cleaningtool disclosed herein consists of components configured with respect toeach other so as to attain the desired objective.

Referring to the drawings, a well cleaning tool is disclosed. Thecleaning tool, designated as numeral 10, generally includes a hollowtubular body 20 that is adapted for connection 21 to a drill string (notshown). The tubular body 20 defines an outer surface 22 in which, aswill be described, scratching elements 40 outwardly extend. The tubularbody 20 further defines a threaded lower end 25 (shown in FIG. 2) havingexternal threads 25A that cooperate with internal threads 26A, 27A of alock nut 26, and end cap 27, respectively.

The tubular body 20 further includes a plurality of passages 24 thatextend through the tubular body 20. As illustrated the passages 24extend generally perpendicular to the longitudinal length of the body20. In the preferred embodiment, one of the passages 24 is positionedabove the other, and the passages 24 are staggered relative to eachother along the longitudinal length of the tubular body 20.

The present invention further includes a cylindrical sleeve 30. Asillustrated the sleeve 30 is sized to receive the tubular body 20 suchthat an internal surface 31 of the sleeve 30 is in frictional engagementwith the outer surface 22 of the tubular body 20.

The cylindrical sleeve 30 further defines an outer surface 32 in which,as will be described the scratching elements 40 outwardly extend. Thesleeve 30 further includes a plurality of passages 34 that extendthrough the sleeve 30. As illustrated the passages 34 extendperpendicular to the longitudinal length of the sleeve 30. In thepreferred embodiment the number of passages 34 in the sleeve 30 beingequal to the number of passages 24 in the tubular body 20.

The tubular body 20 and cylindrical sleeve 30 each include at least two(2) circumferentially arranged passages 24, 34, respectively aspreviously described. In the preferred embodiment, one of the passages34 is positioned above the other, and the passages 34 are staggeredrelative to each other along the longitudinal length of the sleeve 30.In application, the passages 24 are positioned to align with thepassages 34.

The sleeve 30 sliding receives the tubular body 20 such that thepassages 34 of the sleeve 30 are in alignment with the passages 24 ofthe tubular body 20. The scratching element 40 is preferably a rigidcable with frayed ends 42 that is commercially available. A length ofthe rigid cable 40 is operatively positioned through the alignedpassages 24, 34 such that the frayed ends 42 outwardly extend from theouter surface 32 of the sleeve 30. As should be understood, the lengthof the rigid cable 40 is such that only the frayed ends 42 of the rigidcable 40 extend from the outer surface 32 for cleaning the internaldiameter of a well casing. Further, the passages 24, 34 with the ends 42extending therefrom, are preferably staggered along the length of thesleeve 30 to insure full coverage of the circumference of the casing asthe scraper 10 is run axially through the casing.

It will be further understood that the sleeve 30 is not affixed to thetubular body 20 and is retained in position on the body 20 by the rigidcable 40 passing through the aligned passages 24, 34. Thus, in use,aligning the passages 24, 34 (as will be further discussed) and removingthe cables 40 from the passages 24, 34 releases the sleeve 30 forseparating from the tubular body 20.

The present invention also teaches the means of retaining the rigidcable 40 within the passages 24, 34. Once the scratching elements 40 areinstalled as described, threading or tightening the tubular body 20 end25 to the lock nut 26 and end cap 27 in the direction of arrow “A” shownin FIG. 1 will cause the passages 24 out of alignment with passages 34.As the passages 24, 34 move out of alignment, the rigid cable 40 isslightly crimped or pinched 45 between the passages 24, 34, fixing therigid cable 40 in place. With the passages out of alignment asdescribed, the scratching elements 40 are effectively locked intoposition and will not separate from the scraper 10 during operation.

To replace or remove the rigid cable 40, threadably loosen the tubularbody 20 from the end cap 27 in a direction opposite arrow “A” until thepassages 24, 34 are aligned. As the passages 24, 34 move in toalignment, the rigid cable 40 can freely pass through the passages 24,34.

Although the description above contains many specificities, these shouldnot be construed as limiting the scope of the invention but as merelyproviding illustrations of some of the presently preferred embodimentsof this invention. Thus the scope of the invention should be determinedby the appended claims in the formal application and their legalequivalents, rather than by the examples given.

1. A well cleaning tool comprising: a tubular body having an outersurface and a plurality of first passages staggered relative to eachother along a longitudinal length of said tubular body, a cylindricalsleeve sized to releasably receive said tubular body, wherein saidcylindrical sleeve having an internal surface that is in frictionalengagement with said outer surface of said tubular body, saidcylindrical sleeve further including a plurality of second passagesstaggered relative to each other along a longitudinal length of saidcylindrical sleeve, wherein said first passages are in alignment withsaid second passages, a plurality of scratching elements, wherein alength of each of said scratching elements is positioned through saidfirst and second passage and outwardly extends from said second passage,retaining means to pinch said scratching element between said first andsecond passages.
 2. The well cleaning tool as recited in claim 1,wherein said tubular body defines a threaded lower end having externalthreads that cooperate with internal threads of a lock nut and end cap.3. The well cleaning tool as recited in claim 2, wherein tightening saidthreaded lower end to said end cap will cause the first and secondpassages out of alignment causing the scratching element to pinchbetween the first and second passages and retaining said scratchingelement in place.
 4. The well cleaning tool as recited in claim 3,wherein said plurality of scratching elements are rigid cables havingfrayed ends.
 5. The well cleaning tool as recited in claim 4, whereinsaid rigid cable is passed through aligned first and second passagessuch that said frayed ends outwardly extend from said cylindricalsleeve.
 6. The well cleaning tool as recited in claim 1, wherein saidtubular body for connecting to a drill string.
 7. The well cleaning toolas recited in claim 6, wherein said tubular body is a hollow tubularbody.
 8. The well cleaning tool as recited in claim 1, wherein thenumber of first passages is equal to the number of second passages. 9.The well cleaning tool as recited in claim 1, wherein said firstpassages extend generally perpendicular to the longitudinal length ofsaid tubular body.
 10. The well cleaning tool as recited in claim 1,wherein said second passages extend perpendicular to the longitudinallength of said cylindrical sleeve.
 11. The well cleaning tool as recitedin claim 1, wherein aligning the first and second passages and removingthe scratching element from said first and second passages releases thecylindrical sleeve for separating from said tubular body.
 12. A wellcleaning tool comprising: a first body having an outer surface and aplurality of first passages, a second body sized to releasably receivesaid first body, wherein said second body having an internal surfacethat is in frictional engagement with said outer surface, said secondbody including a plurality of second passages, wherein said firstpassages are in alignment with said second passages, at least onescratching elements, wherein a length of each of said at least onescratching elements is positioned through said first and second passageand outwardly extends from said second passage, retaining means tomaintain each of said at least one scratching elements between saidfirst and second passages.
 13. The well cleaning tool as recited inclaim 12, wherein said plurality of first passages are staggeredrelative to each other along a longitudinal length of said first body.14. The well cleaning tool as recited in claim 12, wherein saidplurality of second passages are staggered relative to each other alonga longitudinal length of said second body.
 15. The well cleaning tool asrecited in claim 13, wherein said first passages extend generallyperpendicular to the longitudinal length of said first body.
 16. Thewell cleaning tool as recited in claim 14, wherein said second passagesextend perpendicular to the longitudinal length of said second body. 17.The well cleaning tool as recited in claim 12, wherein said first bodydefines a threaded lower end having external threads that cooperate withinternal threads of a lock nut and end cap.
 18. The well cleaning toolas recited in claim 17, wherein adjusting said lower end such that saidfirst and second passages are out of alignment and said scratchingelement is pinched between said first and second passages and retainingsaid scratching element in place.
 19. The well cleaning tool as recitedin claim 12, wherein said at least one scratching elements are rigidcables having frayed ends, and wherein said rigid cable is passedthrough aligned first and second passages such that said frayed endsoutwardly extend from said second body.
 20. The well cleaning tool asrecited in claim 12, wherein aligning said first and second passages andremoving the scratching element from said first and second passagesreleases the second body for separating from said first body.